Diagnosing new 60Hz/pickup issues...

Discussion in 'Tonefreaks' started by Paranoia, Jul 2, 2017.

  1. Paranoia

    Paranoia Junior Member

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    Howdy all.

    Hoping to get a little help with the bridge pickup on my Les Paul - I plugged it in today and got that horrible 60hz hum through it, which I haven't had before in years of using it... I've spent a good chunk of the afternoon poking around in its guts, though I'm far from an expert at this stuff, and here's what I've found:


    * The bridge pickup now gets 60Hz hum, which is eliminated when I touch a metal component, but gets louder when I touch a non-adjustable polepiece (disappears when I touch an adjustable one).
    * The bridge tone now is very thin, and very quiet - but is otherwise still outputting.
    * The neck pickup still works fine (as does the mid position, in that it's a combination of the neck and what little bridge there is).
    * I was working with steel wool nearby earlier, and did find a fragment magnetically attracted to a polepiece on the bridge pickup (it is not covered). I cleaned it up, unscrewed all the polepieces and brushed them down.
    * Still thinking steel wool, I opened the pickup up, pulled the magnet out and got a fine paintbrush in there to do some dusting, just in case. Everything was put together very tightly, and I can't see any actually having gotten in there, but while I had it open I also visually checked what joints and wires I could see...
    * I checked the switch, input jack and pots- all *looked* fine, but then perhaps they aren't... I used the little paintbrush to do some cleaning, though of course this won't help if there happens to be a bad joint.


    Any ideas on what this could be, or what I could do to fix it? I did do some reading before posting this that did say sometimes solder joints can just go cold... I'm hoping this isn't a dead pickup.

    In any case, any help you could provide is appreciated.
     
    Last edited: Jul 2, 2017
  2. C_Becker

    C_Becker Dat Gibson smell Premium Member

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    Thin sound could indicate a ground problem, check the ground connection on the pots, especially bridge volume pot.
     
  3. ARandall

    ARandall Senior Member

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    Thin I'd guess sounds like only 1 coil working.
     
  4. DarrellV

    DarrellV Likes > Posts Silver Supporter Premium Member

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    I was thinking that!

    Sounds like the slug side open to ground, but connected to signal so when he touches it it gets worse.

    The screw side is is still grounded, but open to hot as it normally goes through the other coil to signal.
     
  5. Paranoia

    Paranoia Junior Member

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    Thanks all for the advice so far.

    I'm at a bit of a loss to explain why it's doing what it's doing, but based on what you guys have posted, and what I read, I've done this:

    * I plugged in the guitar, turned on the amp, put on only the bridge pickup, and then opened the switch cavity. I touched the terminals with a screwdriver, and got noise from the ground terminal, and the bridge terminal (but not bridge/neck, and not neck). All seems good here, I think...
    * I did the same for the control cavity, and got noise from all the non-grounded pot terminals for the bridge pickup upon tapping with a screwdriver. One of the joints sure looks grungy, but otherwise I think that means all is good here too...


    --
    With nothing left to look at, I pulled the humbucker apart, sadly tearing up all that humbucker tape in the process (90% sure that tape was where my tone came from, so it's a sad day). Unsurprisingly, it was all rather clean of steel wool in there.

    It's a waxy mess and I don't have the time tonight to go through it, but there are white and black wires where the two coils meet at one end, so maybe my answer will be there. There's definitely one black wire unattached to anything, but given that it's black, this might be a ground, so that'd be ok.

    Is there anything else I should be looking at while I'm poking around in there? Rather hoping it'll be solvable without needing to buy a new one!

    ---
    [EDIT]: The unattached black wire looks to actually be in a real bad shape, it's kinked and almost snapped at another point. It also comes from the coil that isn't working...
     
    Last edited: Jul 3, 2017
  6. ARandall

    ARandall Senior Member

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    There can be no wires unattached to anything and it still be ok. You require a circuit.
     
  7. Paranoia

    Paranoia Junior Member

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    Thanks for the advice.

    This black wire that wasn't attached to anything looked like it hasn't been attached to anything for a long time - the end wasn't shiny and new. Furthermore, it wasn't inside the coil tape, but between layers...

    I did find a place I'd believed it should go (the only other exposed metal wire part in there!) but this didn't make a change. Either this wire isn't used as I thought it would be and there's some other issue, or, it didn't go where I thought it went.

    In any case, I don't have the tools or equipment to re-pot and do up a pickup properly, so I'm going to get me a new one. This pickup will be a project pickup, when I do get that equipment :p

    Thanks all again for the advice.
     
  8. Dun Ringill

    Dun Ringill Premium Member

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    Did the issue start immediately after using the steel wool?
     
  9. C_Becker

    C_Becker Dat Gibson smell Premium Member

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    Can you take pictures of the pickup, especially the loose wire ?
     

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